Fiber optic adapters are widely used in the field of optical fiber connection equipment. Two ends of the fiber optic adapter can be plugged into fiber optic connectors of different interface types to achieve conversion among various interfaces such as FC, SC, ST, LC, MTRJ, MPO and E2000. To facilitate the connection between the connectors at the two ends and the adapter, the fiber optic adapter is connected to the fiber optic connectors via ports, a sleeve is provided between opposite ports, each of the fiber optic connectors at the two ends of the fiber optic adapter is inserted into a corresponding port, and optical fibers at the heads of the fiber optic connectors are respectively inserted into the fiber optic adapter from the two ends of the sleeve and are aligned by the sleeve to avoid optical fiber dislocation and to reduce losses.
In the related art, to proof dust and light, the fiber optic adapter is provided with a lightproof plate. The lightproof plate typically can rotate in the port so as to avoid an inserted fiber optic connector when the fiber optic connector is inserted and to cover the port when the fiber optic connector is pulled out. In order to mount the lightproof plate, the fiber optic adapter is divided into a body portion and an external clamping portion in an opening direction of the port. The lightproof plate is mounted on a side of the body portion near the port, and the external clamping portion is pressed in, such that the lightproof plate is fixed. In this structure, the body portion and the external clamping portion are clamped in the opening direction of the port, so the external clamping portion protrudes into the port and causes a smaller space in the port.
In addition, a cover is separated, on a port side, from the adapter body of the fiber optic adapter. In this case, the lightproof plate is mounted into the port, the cover covers the side of the port, and then a metal frame is fitted to the adapter body on which the cover has been mounted so as to fix the cover to the adapter body. This type of fixation requires use of the additional metal frame for fixation, not only being inconvenient for fixation, but also increasing the number of components and increasing the complexity of the assembly process.